Tumor regression during maintenance chemotherapy. Mean sums of tumor diameters (panel A) and percentages of tumor regression (panel B) measured at inclusion (D1) and after 3 months (D85, i.e. during induction chemotherapy) and 6 months (D170, i.e. during maintenance chemotherapy) are shown for each dose-group. The four patients with unavailable D170 data were excluded from the analysis. Statistically significant decreases between D85 or D170 and D1 and between D170 and D85 are indicated (see brackets, * p < 0.05). The mean sums of tumor diameters ± sd obtained in the 15 patients who achieved an objective response are shown in panel C (one D170 sum of diameters is missing).